Machine for dry-cleaning articles

ABSTRACT

The machine ( 1 ) for dry-cleaning and drying articles such as clothes, household linen, towels, curtains and the like comprises a rotary drum ( 2 ) which contains the articles, a hydrocarbon—solvent feed and recovery circuit ( 16 ), a powder filter ( 22 ) and a cartridge filter ( 122 ) for filtering the hydrocarbon—solvent.

TECHNICAL FIELD

The present invention relates to a machine for dry-cleaning articles such as clothes, household linen, towels, curtains and the like.

In particular, the present invention relates to a machine for dry-cleaning and drying articles using hydrocarbon-based or silicone-based solvents.

BACKGROUND ART

The above-mentioned hydrocarbon- or silicone-based solvents were introduced in recent years to make up for the high polluting effect of the hydrofluorocarbon-based solvents previously used. The latter type of solvents, although having an extremely high cleaning capacity, proved to be extremely polluting and therefore not very eco-friendly.

The use of hydrofluorocarbon-based solvents, because of the particularly aggressive action both on stains and on colours, meant that for their purification and consequent reuse complex and even dangerous distillation operations were needed, necessitating the integration of complicated and sophisticated devices in the dry-cleaning machines.

The introduction of the new hydrocarbon- or silicone-based solvents, thanks to the fact that they are less aggressive, has allowed the complex distillation step to be avoided, with simple filtering steps being sufficient.

In other words, the solvent already used for dry-cleaning articles is no longer distilled, but is simply filtered using cartridge or powder filters.

Following the filtering step, the solvent can be put back into circulation for subsequent dry-cleaning operations in the machine.

Powder filters of the type normally used operate as follows: the solvent coming out of the container used for dry-cleaning the articles, which is therefore loaded with impurities removed from the articles, is passed through a predetermined quantity of filter powders of the known type, said powders catching the impurities.

Depending on the number of dry-cleaning cycles and other known variables, filters of this type require regular substitution of the powders, since after they have absorbed large quantities of the above-mentioned impurities, the powders lose their filtering capacity.

Cartridge filters operate in a similar way: the solvent coming out of the container used for dry-cleaning the articles, which is therefore loaded with impurities removed from the articles, is passed through a filter cartridge which catches the impurities.

Filtering with powders is basically more economical than cartridge filtering, due to the greater cost of disposing of the filter cartridges.

However, there are limits on the effectiveness of filtering with powders, above all with pale and white clothes. Therefore, if after dry-cleaning dark articles one then dry-cleans a load of white or pale articles, the solvent used often contains traces of the colour of the dark articles previously dry-cleaned and, therefore, said traces of colour damage the pale articles subsequently treated, staining them.

DISCLOSURE OF THE INVENTION

The aim of the present invention is to overcome the above-mentioned disadvantage with a machine for dry-cleaning articles such as clothes, household linen, towels, curtains and the like, which allows the effective and economical execution of dry-cleaning and drying cycles for said articles, whether they are pale or dark, the machine being simple and economical to make and easy and practical to use.

The technical features of the present invention, in accordance with the above aims, are clear from the content of the claims herein, in particular claim 1, and from any of the claims directly or indirectly dependent on claim 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

With reference to the accompanying drawing, the numeral 1 denotes as a whole the machine for dry-cleaning articles such as clothes, household linen, towels, curtains and the like, made in accordance with the present invention.

The machine 1 comprises a drum 2 or container in which the articles to be dry-cleaned are inserted.

The drum 2 rotates, driven by motor elements of the substantially known type not described or illustrated, about an axis of rotation A perpendicular to the plane illustrated.

The machine 1 comprises a system 3 for drying the articles contained in the drum 2 which are not illustrated.

The system 3 comprises an air treatment unit 4, a first section 5 for air infeed into the drum 2, in particular dry, hot air, and a second section 6 for air outfeed from the drum 2.

As described in more detail below, the solvent used for dry-cleaning also comes out of the drum 2 through the second section 6.

The air treatment unit 4 comprises a duct 7 for the passage of the air which is treated, a fan 8 designed to make the air circulate in the duct 7 and the drum 2, a condenser 9 designed to condense the vapours in the treated air, a preheater 10 for the air and an actual heater 11.

The air treatment unit 4 also comprises a filter 12 designed to catch any volatile materials carried by the air flow, such as hairs and threads detached from the articles during drying as well as, at the second, outfeed section 6, a trap 13 for collecting any parts detached from the articles being dry-cleaned, such as buttons, pins or the like.

The machine 1 also comprises, side by side, three storage tanks 14, 15 and 17 for the silicone- or hydrocarbon-based solvent for dry-cleaning the articles, hereinafter also referred to simply as solvent.

The tanks 14, 15, 17 are inserted in a solvent feed and recovery circuit 16 used in the dry-cleaning cycle.

A duct 18 for filling the tanks 14, 15, 17 is connected with the tank 15 and there is an on-off valve 18 a positioned along the duct 18.

In particular, the duct 18 is directly connected to the tank 15 which, in turn, is connected by suitable diaphragms to the other tanks 14 and 17, so that the solvent fed to the tank 15, having reached the level of said diaphragms, is also transferred by pouring off to the tanks 14 and 17, thus filling them.

From the base of the tank 14 there extends a fitting 14 a with a respective stop valve 14 b, the fitting 14 a joining a first inlet stretch 16 a of the feed and recovery circuit 16.

The first stretch 16 a of the circuit 16 is also closed, with a respective arm 14 c, on the top of the tank 14. There is an on-off valve 14 d on the arm 14 c.

Positioned on said first inlet stretch 16 a there is a solvent circulating pump 19 which, sucking the solvent from the tank 14, feeds it to the dry-cleaning drum 2 or to the tank 14 itself, through the valve 14 d.

The tanks 15, 17 feed a second inlet stretch 16 b extending parallel with a portion of the first inlet stretch 16 a, then rejoining the latter at a point P.

In particular, from the base of the two tanks 15, 17 there extend two fittings 15 a, 17 a with respective stop valves 15 b, 17 b, the fittings 15 a, 17 a joining the second inlet stretch 16 b of the feed and recovery circuit 16.

The second stretch 16 b of the circuit 16 is also closed, with respective arms 15 c, 17 c, on the top of the tanks 15, 17. There is an on-off valve 15 d, 17 d on each of the arms 15 c, 17 c.

Similarly to the first stretch 16 a, on the second inlet stretch 16 b there is a solvent circulating pump 119 which, sucking the solvent from the tanks 15, 17, feeds it to the dry-cleaning drum 2 or to the tanks 15, 17 themselves, through the valves 15 d, 17 d.

At an end portion of the inlet stretch 16 a, therefore downstream of the point P at which this intersects with the second inlet stretch 16 b, there is a valve 20 designed to regulate the infeed into the drum 2 of the solvent fed by the pumps 19 and 119.

At the drum 2 second, outfeed section 6, from the trap 13 there extends a third, recovery stretch 16 c of the solvent feed and recovery circuit 16.

At a point labelled P1, the third stretch 16 c forks into two branches, labelled 16 c′ and 16 c″ respectively. The branch 16 c′ joins the first stretch 16 a of the circuit 16, between the valve 14 b and the circulating pump 19, whilst the branch 16 c″ joins the second stretch 16 b, between the valves 15 b, 17 b and the circulating pump 119.

Close to the point P1 both the branch 16 c′ and the branch 16 c″ belonging to the third stretch 16 c have respective on-off valves 21, 121.

A solvent conditioning circuit 16 d extends from the first stretch 16 a of the feed and recovery circuit 16.

The conditioning circuit 16 d comprises a powder filter 22 and, advantageously, a unit 23 for cooling the solvent coming out of the filter 22. An on-off valve 24 is inserted between the powder filter 22 and the cooling unit 23. The cooling unit 23 comprises a heat exchanger 25 in which a known type of refrigerant circulates.

The function of the heat exchanger 25, preferably of the coil type, is to lower the temperature of the solvent before introducing it into the drum 2. Lowering the temperature makes the solvent less aggressive and more suitable for dry-cleaning delicate articles.

As illustrated in the accompanying drawing, the second stretch 16 b converges with the conditioning circuit 16 d downstream of the valve 24. Therefore, from the valve 24 to the point P of intersection with the first stretch 16 a, the second stretch 16 b and the circuit 16 d substantially coincide.

The powder filter 22, forming a first solvent filtering device for the machine 1, is of the substantially known type and designed to house a predetermined quantity of powders which, when the liquid solvent in transit flows through them, catch the impurities transported by the solvent.

A dividing pipe 26 connects the powder filter 22 to the drum 2 second, outfeed section 6, to at least partly discharge the solvent contained in the filter 22, upstream of the third recovery stretch 16 c, according to the direction of the arrow F1.

A respective on-off valve 27 is positioned along the dividing pipe 26.

As illustrated in the accompanying drawing, there is a cartridge filter 122 positioned along the second inlet stretch 16 b. The cartridge filter 122, forming a second solvent filtering device for the machine 1, is of the substantially known type and designed to house a cartridge, not illustrated, designed to catch the impurities transported by the solvent.

There are two on-off valves 131, 124 positioned along the second inlet stretch 16 b, respectively upstream and downstream of the filter 122, according to the direction of the arrow F2.

A check valve 133 is positioned along the second inlet stretch 16 b, downstream of the pump 119 according to the direction of the arrow F6.

In an intermediate position between the check valve 133 and the on-off valve 131, a filter 122 bypass circuit 100 extends from the second stretch 16 b, the bypass circuit 100 reconnecting to the second stretch 16 b downstream of the on-off valve 12-4.

A respective on-off valve 101 is positioned along the bypass circuit 100.

Advantageously, but not necessarily, according to a preferred embodiment, the machine 1 also comprises an element 28 for collecting the powders discharged from the filter 22 after they have exhausted their filtering action.

The collecting element 28 comprises a container 29, having walls permeable both to the air and to the solvent, but able to retain the filter powders.

In other words, the container 29 containment walls consist of a sort of net with a very fine mesh, able to retain the powders but at the same time allow both air and solvent to pass.

Extending from the filter 22 there is a pipe 30 for discharging the powders, the pipe 30 leading into the powder collecting element 28. Two on-off valves are positioned along the discharge pipe 30: one, labelled 31, close to the filter 22 and the other, labelled 32, close to the collecting element 28.

The powder discharge pipe 30 is partly integrated in the solvent feed and recovery circuit 16.

A check valve 33 is positioned alone the first inlet stretch 16 a, downstream of the pump 19 according to the direction of the arrow F2, to prevent the powders from passing towards the pump 19, as described in greater detail below.

There is also an on-off valve 34 on the first inlet stretch 16 a, downstream of the check valve 33.

Advantageously, but not necessarily, the machine 1 comprises a motor, schematically indicated with a block 35, designed to drive the rotation of the container 29 about a respective axis of rotation B.

Extending from the air transit duct 7, downstream of the heater 11 according to the direction of the arrow F3, there is a powder collecting element 28 hot air inlet duct 36. In other words, through the first duct 36, hot air taken from the drying system 3 is sent into the powder collecting element 28.

An air extractor duct 37 extends from the powder collecting element 28 and leads into the air transit duct 7, upstream of the fan 8 according to the direction of the arrow F3.

The air inlet duct 36 and extractor duct 37, together with the air treatment unit 4, form means 38 for drying the powders used in the filter 22.

Advantageously, but not necessarily, the drying means 38 comprise an auxiliary fan 39 positioned along one of the ducts 36, 37 for generating a forced hot air flow in the powder collecting element 28.

With reference to the drawing, a duct 40 for recovering solvent dripped from the powders contained in the container 29 extends from the collecting element 28 and leads into one of the two solvent storage tanks 14, 15.

As illustrated in the accompanying drawing, a first stretch 40 a of the recovery duct 40 is integrated in the air extractor duct 37.

The machine 1 also comprises a first and a second solvent vapour vent pipe 41, 42.

The first vent pipe 41 puts both the powder filter 22 and the cartridge filter 122 in fluid connection with the solvent storage tank 17, whilst the second vent pipe 42 puts the tank 15 in fluid connection with the drum 2 containing the articles.

An air vent valve 102 is positioned along the first vent pipe 41.

A compensation pipe 46 extends from the powder collecting element 28 and leads to the tank 14, to facilitate solvent discharge from the element 28, putting the latter at the same pressure as the tank 14.

In practice, preferably for dry-cleaning dark articles, the pump 19 sends the solvent drawn from the tank 14 through the first inlet stretch 16 a of the circuit 16, with the valve 34 open, towards the dry-cleaning drum 2, according to the path indicated by the arrows F2.

With the valve 20 open, the solvent is introduced into the drum 2 for first filling.

Inside the drum 2, driven in rotation about its axis A by the motor elements not illustrated, the solvent performs its function and dry-cleans articles such as clothes, household linen, towels, curtains and the like.

During article dry-cleaning, the solvent circulates through the feed and recovery circuit 16 and through the drum 2.

In particular, at the drum 2 outfeed, the solvent passes through the trap 13, designed to catch any solid bodies such as pins, buttons or the like carried along by the solvent.

Downstream of the trap 13, the solvent goes into the third, recovery stretch 16 c of the circuit 16 and, after passing through the first branch 16 c′ of the latter and the relative on-off valve 21, it is re-introduced into the first stretch 16 a of the circuit 16 by the sucking action of the pump 19.

Obviously, in such a situation the valve 21 is open, whilst the valve 121 is closed.

Once the drum 2 filling step is complete, the valve 34 is closed and, by opening the valve 31, the solvent made to circulate in the conditioning circuit 16 d then go back into the first stretch 16 a downstream of the valve 34, according to the direction of the arrow F2 and is again introduced into the drum 2.

In other words, after article dry-cleaning has started, the solvent coming out of the drum 2 must be filtered to remove any impurities and dirt from it that came from the articles being dry-cleaned.

Then, as already indicated, the on-off valve 34 is closed and the valve 31 is simultaneously opened. In this way, after passing the check valve 33, the solvent continues towards the powder filter 22 according to the direction of the arrow F4.

In the known ways, inside the powder filter 22 the solvent is filtered and releases dirt and impurities on the filter 22 powders then comes out of the filter and, passing through the valve 24, reaches the cooling unit 23.

Inside the cooling unit 23 the solvent passes through the heat exchanger 25 and its temperature is reduced, then it is re-introduced into the first inlet stretch 16 a of the circuit 16.

When the actual article dry-cleaning steps have finished, with the presence of the solvent in the drum 2, the solvent is discharged from the drum 2 without any new solvent being added to it. Basically, the on-off valve 20 is closed and the valve 14 d is simultaneously opened, so that the solvent circulating along the circuit 16 is directed, through the arm 14 c, to the tank 14.

At this point the drying system 3 is activated, by means of which hot dry air heated by the heater 11 and the preheater 10 is introduced into the drum 2 through the first, infeed section 5.

The hot air becomes loaded with solvent vapours still present in the articles dry-cleaned in the drum 2 and comes out of the drum through the second, outfeed section 6, thanks to the action of the fan 8.

The hot air extracted from the drum 2 is therefore moist, unlike the hot air introduced into the drum which is substantially dry.

The moist hot air extracted from the drum 2 passes through, one after another according to the direction of the arrow F3, the trap 13 and the filter 12 designed to catch any volatile materials carried by the air flow.

After passing through the filter 12, the flow of hot moist air, still driven by the action of the fan 8 and proceeding according to the direction of the arrow F3, reaches the condenser 9 where the moist component of the air is at least partly condensed. In practice, the solvent transported by the air in the form of vapour is condensed and the condensed liquid solvent is carried, by a special pipe 43, towards the solvent storage tanks 14, 15, 17.

In reality, the product of air condensation may comprise, not just liquid solvent, but also some water that was present in the air.

As illustrated in the accompanying drawing, to re-introduce solvent that is substantially pure and free of water residues into the tanks 14, 15, 17, a water-solvent separator 45 is used, positioned along the pipe 43.

After passing through the condenser 9 and losing its moisture, the air therefore becomes dry and continues to pass through the duct 7. In particular, downstream of the condenser 9, according to the direction of the arrow F3, the dry air flow passes through the preheater 10 and the heater 11 which heat it and return it to the predetermined temperature for effective drying of the articles located in the drum 2.

The hot air continues to circulate in the drum 2 until the articles in the drum 2 reach the required level of dryness.

After a predetermined number of dry-cleaning cycles, the filter powders in the filter 22 will have accumulated a quantity of dirt and impurities which compromises the efficiency of the solvent filtering action.

Therefore, the used powders must be substituted with new powders.

Before substituting or changing the powders, it is a good idea to reduce the level of solvent normally standing in the filter 22.

Therefore, the pump 19 is stopped and the valve 27 on the dividing pipe 26 opened. Through the latter, part of the solvent contained in the filter 22 is conveyed towards the second, outfeed section 6 and from there into the third, recovery stretch 16 c of the circuit 16.

After the required quantity of solvent has come out of the filter 22, the valve 27 is closed and, by means of a motor 22 a operatively connected to the filter 22, part of the filter 22 is rotated in such a way as to detach the filter powders from the filter 22 walls by shaking.

Once filter powder shaking is complete, the on-off valves 31 and 32 are opened.

With the valves 31 and 32 open, the mixture of powders and solvent still contained in the filter 22 flows, under the effect of gravity, along the discharge pipe 30 according to the direction of the arrow F5, until it reaches the powder collecting element 28.

Once the filter powders impregnated with solvent have been discharged from the filter 22 to the collecting element, new filter powders can be inserted in the filter 22 and, after closing the valves 31, 32 again, the pump 19 can be activated again to re-establish the normal solvent flow along the circuit 16 to and from the drum 2.

For a functional description of operations involving the powder collecting element 28 and the consequent powder drying steps, full reference is made to the content of the description of prior Italian patent application BO2005A000648, in the name of the same Applicant. Said material referred to regarding the powder discharge and drying steps shall therefore be considered an integral part of this text.

The powders collected in the element 28 are therefore dried and so can be disposed of with the obvious advantage of having recovered the solvent which they retained when they came out of the filter 22 and which would otherwise have been thrown away.

The above functional description of the machine 1 related to machine 1 operation with the solvent fed from the tank 14 and filtered through the powder filter 22, forming a first solvent filtering device for the machine 1.

As already indicated in the introduction to this description, the use of powder filtering may not be effective when the colour of the articles handled is pale or white.

According to the present invention, for dry-cleaning pale or white articles, such as clothes, household linen, towels, curtains and the like, solvent filtered by the cartridge filter 122 is advantageously used, the latter forming a second solvent filtering device for the machine 1.

Therefore, in practice, preferably during a dry-cleaning cycle for pale articles, the pump 119 sends the solvent drawn from the tanks 15, 17 through the second inlet stretch 16 b of the circuit 16, towards the dry-cleaning drum 2, according to the path indicated by the arrows F6.

With the valve 20 open, the solvent is introduced into the drum 2 for first filling.

In detail, the solvent drawn without distinction from the tanks 15 and 17 is fed by the pump 119 along the second stretch 16 b and, with the on-off valves 131 and 124 closed, through the cartridge filter 122 bypass circuit 100.

This being a first filling operation, the solvent drawn from the tank 15 and/or 17 has still not collected impurities from the articles being dry-cleaned and therefore, assuming that it does not need any filtering, can be fed directly to the drum 2.

Downstream of the bypass circuit 100, the solvent passes through the cooling unit 23 then reaches the point P of intersection and re-introduction into the final part of the first stretch 16 a. The solvent passes through the final part of the first stretch 16 a in the direction indicated by the arrows F2, similarly to what is described above with reference to the solvent arriving from the tank 14 and to be filtered in the powder filter 22.

When its time in the drum 2 has finished, depending on the schedule of the predetermined dry-cleaning cycle, at the drum 2 outfeed, the solvent passes through the trap 13, designed to catch any solid bodies such as pins, buttons or the like carried along by the solvent.

Downstream of the trap 13, the solvent goes into the third, recovery stretch 16 c of the circuit 16 and, after passing through the second branch 16 c″ of the latter and the relative on-off valve 121, it is re-introduced into the second stretch 16 b of the circuit 16 by the sucking action of the pump 119.

Obviously, in such a situation the valve 121 is open, whilst the valve 21 is closed.

Once the drum 2 filling step is complete, the valve 101 is closed and, by opening the valves 131 and 124, the solvent made to circulate through the cartridge filter 122, then go back, filtered and so without dirt and impurities, into the first stretch 16 a at the point P where the sections 16 a, 16 b and 16 d intersect.

From the point P, according to the direction of the arrow F2, the solvent filtered and cooled by passing through the cooling unit 23 is re-introduced into the drum 2.

In other words, after article dry-cleaning has started, the solvent coming out of the drum 2 must be filtered to remove any impurities and dirt from it that came from the articles being dry-cleaned.

When the actual article dry-cleaning steps have finished, with the presence of the solvent in the drum 2, the solvent is discharged from the drum 2 without any new solvent being added to it. Basically, the on-off valve 20 is closed and at least one of the valves 15 d, 17 d is simultaneously opened, so that the solvent circulating along the circuit 16 is directed, through the respective arms 15 c, 17 c, to the tank 15 or 17.

Similarly to what is described above relative to the cycle for dry-cleaning dark articles, the pale or white articles are also dried inside the drum 2. To keep the description brief, these steps, being identical, are therefore not described again.

The machine disclosed advantageously achieves the preset aim of allowing an effective and economical dry-cleaning cycle for dark articles, with filtering of the solvent used in a powder filtering device and simultaneously allowing effective dry-cleaning cycles for pale articles, with filtering of the solvent in a cartridge filter.

According to other embodiments of the present invention, not illustrated, there are three filtering devices operating in parallel, of which two are cartridge filtering devices and one is a powder filtering device.

According to yet other embodiments of the present invention, not illustrated, there are three filtering devices operating in parallel, of which two are powder filtering devices and one is a cartridge filtering device.

In this text the term hydrocarbon or hydrocarbon—solvent refers to any type of solvent used for dry-cleaning articles such as clothes and the like, which is hydrocarbon-based or comprising hydrocarbons, in particular synthetic hydrocarbons and/or siloxanes.

By way of example, several type of solvents belonging to the category indicated or similar to it are commercially known as Actrel® 3356 D, Actrel® DF 2000, GreenEarths^(SM).

The invention described above may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements. 

1. A machine for dry-cleaning articles such as clothes and the like, comprising: a rotary drum (2) for containing the articles, a solvent feed and recovery circuit (16) to and from the rotary drum (2), the machine being characterised in that it comprises a first, powder filtering device (22) for the solvent and a second, cartridge filtering device (122) for the solvent, the devices (22, 122) being positioned along the circuit (16).
 2. The machine according to claim 1, characterised in that the first, powder filtering device (22) and the second, cartridge filtering device (122) are positioned parallel with one another so that they can operate alternatively to one another.
 3. The machine according to claim 1, characterised in that, for each filtering device (22, 122) it comprises at least one respective solvent tank (14, 15, 17), each tank (14, 15, 17) being selectively in fluid connection with only one of the filtering devices (22, 122).
 4. The machine according to claim 1, characterised in that the solvent feed and recovery circuit (16) comprises a first inlet stretch (16 a) along which the first filtering device (22) is positioned, and a second inlet stretch (16 b) along which the second filtering device (122) is positioned.
 5. The machine according to claim 4, characterised in that, for each of the inlet stretches (16 a, 16 b) of the feed and recovery circuit (16), it comprises a respective solvent circulating pump (19, 119).
 6. The machine according to claim 5, characterised in that it comprises, extending from the second inlet stretch (16 b), a second, cartridge filtering device (122) bypass duct (100).
 7. The machine according to claim 1, characterised in that it comprises means (23) for cooling the solvent to be fed to the drum (2).
 8. The machine according to claim 7, characterised in that the cooling means (23) are positioned along the feed and recovery circuit (16) downstream of the first and second filtering devices (22, 122).
 9. The machine according to claim 1, characterised in that it comprises an element (28) for collecting the powders discharged from the powder filtering device (22) and drying means (38) for drying said powders in the collecting element (28). 